12 Accessibility Problems That Automated Tools Fail to Detect

A website passes an automated accessibility scan with flying colors. The dashboard shows zero errors, and you're feeling confident. But when a screen reader user attempts to navigate the site-or someone tries to operate it with a keyboard only-the experience falls apart.

Automated accessibility testing tools are useful, no doubt. They speed up checks, catch many critical issues, and help enforce web standards like WCAG. But they’re not infallible. Many nuanced and contextual issues fly under the radar, and relying on automation alone can give a false sense of compliance.

To build truly inclusive digital experiences, human insight is essential. Below, we explore 12 real accessibility problems that automated tools often miss-and why it’s vital to complement automation with manual testing.

Missing or Unclear Link Purpose

Automated tools can check whether a link exists and whether it includes text, but they can’t always judge if the purpose of that link is clear.

Why it matters:

Screen reader users rely on link text to understand where the link will take them. If you have multiple “Click here” links or vague labels, it’s nearly impossible to distinguish them when read out of context.

Common mistakes:

• Using “Read more” repeatedly without context
• Links within body text not explaining their destination
• Buttons styled as links but not conveying purpose

A manual reviewer can evaluate clarity and ensure every link communicates its intent.

Poor Heading Structure

Automated tools can confirm that heading tags exist, but they can’t interpret whether the heading structure logically guides users through the content.

What a developer should look for:

• Improper heading nesting (e.g., jumping from <h1> to <h4>)
• Headings used for visual styling rather than actual structure
• Pages that lack headings altogether or use too many

For screen reader users, headings are like road signs. They provide a sense of hierarchy and allow users to jump to the content they need. Only a human can judge whether those signs make sense.

Inaccessible Visual Focus

Focus indicators show users where they are on the page-especially important for keyboard-only navigation. While tools can check whether focus styles exist, they can't determine if those styles are visible or usable.

Manual checks are needed for:

• Ensuring focus is not lost or trapped on modal windows
• Verifying that focus outlines are visually distinct
• Testing whether tabbing flows logically through interactive elements

When these break, users may get lost and unable to complete essential tasks.

Color Contrast in Context

Automated tools can evaluate contrast ratios, but they don’t always account for overlapping elements, images behind text, or dynamically changing content that interferes with readability.

What can go unnoticed:

• Text over gradients or background videos
• Hover/focus states with poor contrast
• Dynamic banners that change contrast based on time or theme

Only manual testers, especially those with visual impairments, can assess real-world legibility across different lighting and device settings.

Form Errors Without Accessible Feedback

Forms are among the most complex interactive elements, and while tools can catch basic labeling issues, they often miss dynamic errors that are announced incorrectly-or not at all.

Key problems include:

• Error messages not tied to the relevant input field
• Instructions not repeated for screen readers
• Autofocus or validation that interrupts assistive technology
• Placeholder text used instead of labels

A human tester ensures error states, validation messages, and instructions are communicated clearly through multiple modalities-not just visually.

Meaningless Alt Text or Missing Image Context

Automated tools will flag missing alt attributes, but they can’t tell if the alternative text is useful-or whether the image needs a description at all.

Only a human can evaluate:

• Whether the image conveys important information
• If the alt text accurately describes the image’s purpose
• If decorative images are marked properly to be ignored by screen readers

Even worse, tools won’t catch if the alt text is misleading or stuffed with keywords, which only confuses users.

Non-Descriptive Button Labels

A button might be coded correctly and pass structural checks, but its label could be unhelpful, vague, or repetitive.

Examples of weak labels:

• “Submit” without context
• “Go” buttons with no destination description
• Icons used as buttons without accessible names

A visually hidden label or ARIA description may be necessary-something automated tools can’t reliably suggest or verify.

Dynamic Content Without Proper Announcements

Live regions, modals, and pop-ups often change the content without reloading the page. Tools might confirm that ARIA roles exist, but they can’t tell if screen readers actually announce these changes as expected.

Potential problems:

• Toast messages that disappear before assistive tech can read them
• Content updates that are invisible to screen reader users
• Modal dialogs without appropriate focus management

These are critical to user interaction, and only a manual test can confirm their behavior.

Non-Keyboard Accessible Custom Widgets

Sliders, tab panels, date pickers, and carousels are notoriously difficult to make accessible. They may “look fine” to an automated scan, but be unusable without a mouse.

Issues often overlooked:

• Arrow keys or spacebar not functioning
• No keyboard mechanism to exit widgets
• Incomplete ARIA role implementation

Manual testing ensures real interactivity-not just theoretical compliance.

Motion and Animation Barriers

Tools generally don’t test whether motion-based interactions or flashing animations meet user safety needs. This includes parallax effects, scroll-triggered animations, and videos.

Why this matters:

• Fast flashing can trigger seizures
• Constant motion creates cognitive load
• Elements that move unpredictably can disorient users with vestibular disorders

Human reviewers verify whether animations are necessary, subtle, and dismissible.

Language Use and Readability

Even if your content passes structural tests, that doesn’t mean it’s understandable. Automated tools can't measure whether text uses plain language or if directions are easy to follow.

Manual review checks for:

• Jargon, idioms, or complex sentence structures
• Reading level appropriateness for the audience
• Instructions that are overly technical or ambiguous

Readability isn’t just a writing style-it’s a core part of accessibility for users with cognitive impairments or non-native speakers.

Lack of User Testing and Feedback Integration

No tool-automated or manual-can fully substitute for real-world user testing. Users bring context, lived experience, and diverse accessibility needs that no checklist can predict.

Common findings from user feedback:

• Unexpected navigation traps
• Content order that confuses assistive tech
• Layouts that make assumptions about how users interact with content

User feedback completes the accessibility picture, especially when paired with tool results and manual reviews.

Accessibility Is a Human-Centered Practice

Automated tools are valuable. They catch basic errors, speed up QA processes, and enforce standard guidelines. But accessibility is more than code-it’s about people, their behaviors, and how they engage with your digital content.

The only way to ensure a truly inclusive experience is to pair automation with human judgment. From evaluating context to simulating real usage, manual testing fills the gaps no machine can fully close.

If You Suffer These Types of Problems in Your Website & You Need to Automated Accessibility Testing…

You can try automated accessibility testing tools to streamline your audits. But to fully address these challenges, explore some automated accessibility testing service provider companies. They offer experienced teams who combine automation with expert manual testing to ensure your site is both compliant and genuinely usable.

Reference Article :What Automated Web Accessibility Checkers Can’t Catch: 12 Key Problems

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